Major coronary risk factors and death from coronary heart disease: baseline and follow-up mortality data from the Second National Health and Nutrition Examination Survey (NHANES II).

BACKGROUND: Although the major risk factors for coronary heart disease (CHD) are well-established, intense efforts persist in the search for "novel" or "emerging" risk factors because of the notion that as many as half of CHD victims may not have the traditional risk factors.
OBJECTIVE: Compare prevalences of major risk factors among persons with fatal CHD in a nationally representative population sample.
METHODS: Baseline data from the Second National Health and Nutrition Examination Survey and 17-year follow-up mortality data were examined for 8,069 adults (3,701 men; 4,368 women) aged 30 to 75 years in 1976-1980. We calculated sex-specific prevalences of hypertension, elevated total cholesterol (> or = 240 mg/dL), cigarette smoking, and the presence of at least one of these three major risk factors. The relative risk of death from CHD associated with the three major risk factors was calculated in sex-specific multivariable models adjusted for age, race, and education.
RESULTS: Overall, nearly 75% of US adults had at least one of the three major risk factors. Those who died of CHD, compared to those who did not die of CHD, had respectively, greater prevalences of hypertension (men: 48% vs. 38%; women: 76% vs. 33%). Similarly, persons who had fatal CHD were more likely to have elevated total cholesterol (men: 53% vs. 30%; women: 55% vs. 34%), although the finding was not statistically significant in women. Smoking prevalence was also greater among persons who died of CHD than those who did not for both men (64% vs. 40%) and women (43% vs. 33%). The proportion of persons with at least one of the three major risk factors was significantly (P < or = 0.01) greater among those who died from CHD compared with those who did not (men: 92% vs. 74%; women: 98% vs. 70%). The risk of fatal CHD was 51% lower among men and 71% lower among women with none of the 3 risk factors compared to those with at least one. Had all three major risk factors not occurred, 64% of all CHD deaths among women and 45% of all CHD deaths among men could have been avoided.
CONCLUSIONS: Nine out of ten US adults who died of CHD had at least one of the three major established risk factors. Thus, the notion that many CHD victims do not have the traditional risk factors is a misconception. Policies and strategies that increase the prevalence of a low risk profile are needed, and aggressive efforts in the prevention and control of the major established risk factors remain the key to continued reductions in CHD mortality.